+ run_async_handler_and_reschedule (scb);
+}
+
+/* Wait for input on scb, with timeout seconds. Returns 0 on success,
+ otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */
+
+/* NOTE: Some of the code below is dead. The only possible values of
+ the TIMEOUT parameter are ONE and ZERO. OTOH, we should probably
+ get rid of the deprecated_ui_loop_hook call in do_ser_base_readchar
+ instead and support infinite time outs here. */
+
+static int
+ser_base_wait_for (struct serial *scb, int timeout)
+{
+ while (1)
+ {
+ int numfds;
+ struct timeval tv;
+ fd_set readfds, exceptfds;
+ int nfds;
+
+ /* NOTE: Some OS's can scramble the READFDS when the select()
+ call fails (ex the kernel with Red Hat 5.2). Initialize all
+ arguments before each call. */
+
+ tv.tv_sec = timeout;
+ tv.tv_usec = 0;
+
+ FD_ZERO (&readfds);
+ FD_ZERO (&exceptfds);
+ FD_SET (scb->fd, &readfds);
+ FD_SET (scb->fd, &exceptfds);
+
+ QUIT;
+
+ nfds = scb->fd + 1;
+ if (timeout >= 0)
+ numfds = interruptible_select (nfds, &readfds, 0, &exceptfds, &tv);
+ else
+ numfds = interruptible_select (nfds, &readfds, 0, &exceptfds, 0);
+
+ if (numfds <= 0)
+ {
+ if (numfds == 0)
+ return SERIAL_TIMEOUT;
+ else if (errno == EINTR)
+ continue;
+ else
+ return SERIAL_ERROR; /* Got an error from select or
+ poll. */
+ }
+
+ return 0;
+ }
+}
+
+/* Read any error output we might have. */
+
+static void
+ser_base_read_error_fd (struct serial *scb, int close_fd)
+{
+ if (scb->error_fd != -1)
+ {
+ ssize_t s;
+ char buf[GDB_MI_MSG_WIDTH + 1];
+
+ for (;;)
+ {
+ char *current;
+ char *newline;
+ int to_read = GDB_MI_MSG_WIDTH;
+ int num_bytes = -1;
+
+ if (scb->ops->avail)
+ num_bytes = (scb->ops->avail)(scb, scb->error_fd);
+
+ if (num_bytes != -1)
+ to_read = (num_bytes < to_read) ? num_bytes : to_read;
+
+ if (to_read == 0)
+ break;
+
+ s = read (scb->error_fd, &buf, to_read);
+ if ((s == -1) || (s == 0 && !close_fd))
+ break;
+
+ if (s == 0 && close_fd)
+ {
+ /* End of file. */
+ if (serial_is_async_p (scb))
+ delete_file_handler (scb->error_fd);
+ close (scb->error_fd);
+ scb->error_fd = -1;
+ break;
+ }
+
+ /* In theory, embedded newlines are not a problem.
+ But for MI, we want each output line to have just
+ one newline for legibility. So output things
+ in newline chunks. */
+ gdb_assert (s > 0 && s <= GDB_MI_MSG_WIDTH);
+ buf[s] = '\0';
+ current = buf;
+ while ((newline = strstr (current, "\n")) != NULL)
+ {
+ *newline = '\0';
+ fputs_unfiltered (current, gdb_stderr);
+ fputs_unfiltered ("\n", gdb_stderr);
+ current = newline + 1;
+ }
+
+ fputs_unfiltered (current, gdb_stderr);
+ }
+ }
+}
+
+/* Event-loop callback for a serial's error_fd. Flushes any error
+ output we might have. */
+
+static void
+handle_error_fd (int error, gdb_client_data client_data)
+{
+ serial *scb = (serial *) client_data;
+
+ ser_base_read_error_fd (scb, 0);
+}
+
+/* Read a character with user-specified timeout. TIMEOUT is number of
+ seconds to wait, or -1 to wait forever. Use timeout of 0 to effect
+ a poll. Returns char if successful. Returns SERIAL_TIMEOUT if
+ timeout expired, SERIAL_EOF if line dropped dead, or SERIAL_ERROR
+ for any other error (see errno in that case). */
+
+static int
+do_ser_base_readchar (struct serial *scb, int timeout)
+{
+ int status;
+ int delta;
+
+ /* We have to be able to keep the GUI alive here, so we break the
+ original timeout into steps of 1 second, running the "keep the
+ GUI alive" hook each time through the loop.
+
+ Also, timeout = 0 means to poll, so we just set the delta to 0,
+ so we will only go through the loop once. */
+
+ delta = (timeout == 0 ? 0 : 1);
+ while (1)
+ {
+ /* N.B. The UI may destroy our world (for instance by calling
+ remote_stop,) in which case we want to get out of here as
+ quickly as possible. It is not safe to touch scb, since
+ someone else might have freed it. The
+ deprecated_ui_loop_hook signals that we should exit by
+ returning 1. */
+
+ if (deprecated_ui_loop_hook)
+ {
+ if (deprecated_ui_loop_hook (0))
+ return SERIAL_TIMEOUT;
+ }
+
+ status = ser_base_wait_for (scb, delta);
+ if (timeout > 0)
+ timeout -= delta;
+
+ /* If we got a character or an error back from wait_for, then we can
+ break from the loop before the timeout is completed. */
+ if (status != SERIAL_TIMEOUT)
+ break;
+
+ /* If we have exhausted the original timeout, then generate
+ a SERIAL_TIMEOUT, and pass it out of the loop. */
+ else if (timeout == 0)
+ {
+ status = SERIAL_TIMEOUT;
+ break;
+ }
+
+ /* We also need to check and consume the stderr because it could
+ come before the stdout for some stubs. If we just sit and wait
+ for stdout, we would hit a deadlock for that case. */
+ ser_base_read_error_fd (scb, 0);
+ }
+
+ if (status < 0)
+ return status;
+
+ do
+ {
+ status = scb->ops->read_prim (scb, BUFSIZ);
+ }
+ while (status < 0 && errno == EINTR);
+
+ if (status <= 0)
+ {
+ if (status == 0)
+ return SERIAL_EOF;
+ else
+ /* Got an error from read. */
+ return SERIAL_ERROR;
+ }
+
+ scb->bufcnt = status;
+ scb->bufcnt--;
+ scb->bufp = scb->buf;
+ return *scb->bufp++;
+}
+
+/* Perform operations common to both old and new readchar. */
+
+/* Return the next character from the input FIFO. If the FIFO is
+ empty, call the SERIAL specific routine to try and read in more
+ characters.
+
+ Initially data from the input FIFO is returned (fd_event()
+ pre-reads the input into that FIFO. Once that has been emptied,
+ further data is obtained by polling the input FD using the device
+ specific readchar() function. Note: reschedule() is called after
+ every read. This is because there is no guarentee that the lower
+ level fd_event() poll_event() code (which also calls reschedule())
+ will be called. */
+
+int
+generic_readchar (struct serial *scb, int timeout,
+ int (do_readchar) (struct serial *scb, int timeout))
+{
+ int ch;
+ if (scb->bufcnt > 0)
+ {
+ ch = *scb->bufp;
+ scb->bufcnt--;
+ scb->bufp++;
+ }
+ else if (scb->bufcnt < 0)
+ {
+ /* Some errors/eof are are sticky. */
+ ch = scb->bufcnt;
+ }
+ else
+ {
+ ch = do_readchar (scb, timeout);
+ if (ch < 0)
+ {
+ switch ((enum serial_rc) ch)
+ {
+ case SERIAL_EOF:
+ case SERIAL_ERROR:
+ /* Make the error/eof stick. */
+ scb->bufcnt = ch;
+ break;
+ case SERIAL_TIMEOUT:
+ scb->bufcnt = 0;
+ break;
+ }
+ }
+ }
+
+ /* Read any error output we might have. */
+ ser_base_read_error_fd (scb, 1);
+